RESUMEN
<p><b>AIM</b>To establish a method for determinate of the inhibitory activity of angiotensin-converting enzyme inhibitor captopril by high performance capillary electrophoresis.</p><p><b>METHODS</b>The characteristic absorptive wavelength of hippuric acid determined by ultraviolet spectrophotometer is 228 nm. The method employed a melted capillary column, 50 mmol.L-1 phosphoric acid (pH 8.3) buffer solution, inject pressure 4.8 kPa, inject time 3 s, separation voltage 20 kV and detection wavelength 228 nm.</p><p><b>RESULTS</b>The reactant and resultant was separated completed within 7 min. IC50 of captopril was 0.019 mumol.L-1. Captopril is a competitive inhibitor, which was proved by enzyme reaction dynamics.</p><p><b>CONCLUSION</b>The method was shown to be accurate, simple and rapid and can be used for determination of the inhibitory activity of captopril.</p>